Re: Dogs on pontoons
Without thinking a lot about it, I would take one ramp of the pair of pick-up loaders for lawn mowers or ATVs and attach one to the deck and with a float about a foot above the end going into the water make a doggy ramp.
You could fabricate one out of a short single ladder with a plywood center or all sorts of things that would stow easily. Let's face it, trying to wrestle a wet dog onto a deck in water is not the easiest thing to do.
Luck on the doggy ramp